Unless otherwise indicated herein, the approaches described in this section are not prior art to the claims in this application and are not admitted to be prior art by inclusion in this section.
As the use of cellular telephones and other wireless communication devices becomes ubiquitous, the number of commercial and other wireless services available to wireless device users besides ordinary voice and data communications has also increased. Some wireless services rely on the wireless network serving a wireless device to provide the geographic location of the wireless device (and thus its user) to enable or enhance the intended functionality of the service. Such services may be provided by the operator of the wireless network or by a third party.
One such service that is particularly well known is “enhanced 911” (E-911), which automatically delivers the location of a wireless device user to the dispatch center, or public service access point (PSAP), when the user places a call to 911 for emergency services. Such location information can be critical since a caller is often unable to inform the 911 operator verbally of his or her location and, because the call is not being made over a land line, there is no physical address associated with the calling party. Other wireless services available include a growing number of commercial location-based services (LBSs), such as information or entertainment services. LBSs may be selectively delivered or offered to individual wireless device users based on user proximity to a particular location, or may be customized based on the user's current location. Thus, in addition to basic voice and data communications, a cellular telephone or other wireless communication device can provide many other important and convenient services to its user if its location can be determined.